A trampoline generally comprises a rebounding mat fixed to a support frame supported above the ground. A user jumps or bounces on the mat. Usually, trampolines are equipped with a safety enclosure, which extends upwards from the mat to surround or enclose the mat to prevent a user from falling from the trampoline Typically the safety enclosure is formed from mesh or netting and is supported in position by poles which extend upwards from around the edge of the trampoline. Usually these poles are connected to the frame.
A conventional trampoline incorporates a peripheral metal frame with the mat tensioned within frame by extension springs spaced about the edge of the mat and extending outwards from the mat to the frame. An example of this type of trampoline design is shown in FIG. 1b. The trampoline may have a safety enclosure held in position by a number of enclosure support members.
U.S. Pat. No. 6,319,174 discloses a form of soft-edged trampoline in which the mat of the trampoline is supported by a plurality of resiliently flexible rods received in a frame of the trampoline at the lower ends of the rods, the upper end of the rods coupled to the periphery of the bouncing or rebounding mat of the trampoline, this arrangement avoiding the need for a solid frame about the exterior of the bouncing mat, and exposed springs between the frame and periphery of the mat. The rods are angled or spiralled around the frame, extending outwards and upwards from the frame. An example of this type of arrangement is shown in FIG. 1a. Again the trampoline may have a safety enclosure held in position by a number of enclosure support members.
U.S. Pat. Nos. 6,053,845 and 7,854,687 disclose enclosures similar to those shown in FIGS. 1a and 1b. 
U.S. Pat. No. 6,663,538 discloses a trampoline in which the mat is supported by a series of plane springs formed from a material such as steel, the plane springs having the shape of pre-curved flat bars, the lower part of the bars forming a base for the trampoline. The bars are formed to have a ‘Z’-shape or a recurved shape, bending outwards, then inwards, and then outwards again before connecting to the edge of the mat.